If an object is placed at the point F, the magnification of its image will be-

Think it through first, then pick an option.

a less than 1
b more than 1
c equal to 1
d infinite (∞)

Answer and explanation

Correct answer: d infinite (∞)

With the object at F the reflected rays are parallel and the image is at infinity, so the magnification is infinite (∞). The nearer the object to F, the larger the image.

Why the other options are wrong

a less than 1: This is not the answer: less than 1 (m < 1) is for an object beyond C. Towards the focus the image grows, it does not shrink.
b more than 1: This is not the answer: more than 1 is for an object between C and F, with a limited value. At F it has no limit, so saying only more than 1 says too little.
c equal to 1: This is not the answer: equal to 1 (m = 1) is for an object at C.